Calibration Standards Shelf Life
We provide buffers and calibration solutions for our water quality meters that have shelf lives or expiration times that should be adhered to. Since your data is only as good as your calibration, we recommend understanding the expiration dates of the solutions you use. 
(Expiration times for unopened/unmixed solutions are from the date of manufacture, not the date of purchase. Expiration dates are clearly labeled on the bottles.)
- Unopened - Glass Quarts = 1 year
- Unopened - Plastic Pints = 18 months
- Opened = 1 month
Zobell Solution (used for ORP/Oxidation Reduction Potential)
- Unmixed = 5 years
- Mixed = 6 months
- Unopened = 2 years
- Opened = 2 months
- Unopened = 2 years
- Opened = 3 months
- Unopened = 1 year
- Opened = 6 months
- Unopened = 18 months
- Opened = 6 months
- Unopened = 1 year
- Opened = 6 months
Dissolved Oxygen Probe Electrolyte Solution
- Unmixed Crystals = No Stated Expiration
- Mixed Solution = 1 year
Platinizing Solution (used on conductivity cells)
TruLine ISE Calibration, ISA, and Filling Solutions
- Unopened = 15 months
- Opened = 6 months
NOTE: Expiration times for unopened/unmixed solutions are from date of manufacture, no date of purchase. Expiration dates are clearly labeled on the bottle. TruLine solutions are for the TruLine laboratory ISEs.
Additional Blog Posts of Interest:
YSI Expert Tip 5 of 7 - Get Your Water Quality Sonde Field Ready
The Ultimate pH Primer - Are You Familiar with Hydrogen?
Extend the Life of Your pH Electrode in 3 Practical Steps
A Step-by-Step Guide to Installing Stretch-Over DO Membranes